Validity of a Claims-Based Diagnosis of Obesity Among Medicare Beneficiaries.

Population-level data on obesity are difficult to obtain. Claims-based data sets are useful for studying public health at a population level but lack physical measurements. The objective of this study was to determine the validity of a claims-based measure of obesity compared to obesity diagnosed with clinical data as well as the validity among older adults who suffer from chronic disease. This study used data from the National Health and Nutrition Examination Survey 1999-2004 for adults aged ≥ 65 successfully linked to 1999-2007 Medicare claims (N = 3,554). Sensitivity, specificity, positive and negative predictive values, κ statistics as well as logistic regression analyses were computed for the claims-based diagnosis of obesity versus obesity diagnosed with body mass index. The claims-based diagnosis of obesity underestimates the true prevalence in the older Medicare population with a low sensitivity (18.4%). However, this method has a high specificity (97.3%) and is accurate when it is present. Sensitivity was improved when comparing the claim-based diagnosis to Class II obesity (34.2%) and when used in combination with chronic conditions such as diabetes, congestive heart failure, chronic obstructive pulmonary disease, or depression. Understanding the validity of a claims-based obesity diagnosis could aid researchers in understanding the feasibility of conducting research on obesity using claims data.

Medicaid prescription drug spending in the 1990s: a decade of change.

Medicaid spending increased dramatically during the 1990s, driven in part by spending for prescription drugs. From 1990 to 2000, Medicaid drug spending increased from $4.4 billion to over $20 billion, an average annual increase of 16.3 percent. Disabled persons experienced an even greater 20 percent average annual increase. By drug category in 1997 (for 29 States), the highest spending amount was for central nervous system (CNS) drugs, accounting for 17 percent of total Medicaid drug spending. These findings provide information on drug spending for dually eligible beneficiaries to policymakers as they seek to target cost-effective coverage and drug therapies.

Medicaid spending and utilization for central nervous system drugs.

Prior research has shown that prescription drug spending grew substantially during the decade of the 1990s. This analysis uses 1996 to 1998 State Medicaid Research File (SMRF) fee-for-service (FFS) data for 29 participating States to provide insight into the factors driving this growth. The analysis examines cost variation by census region, State, Medicaid basis of eligibility, and therapeutic use of drugs. In 1998, the highest expenditures were for central nervous system (CNS) drugs and for anti-psychotics compared to three other groups of CNS drugs (anti-anxiety agents, anti-depressants, and hypnotics). By eligibility group, expenditures were typically highest for disabled enrollees. There were major variations among SMRF States and their respective regions.